1. Field of the Invention
This invention relates to an oily composition for external application having transparent or semi-transparent appearance and providing excellent retentivity and extendibility on the skin and adhesive capability to the skin.
2. Description of the Background Art
Oily compositions for external application include, for example, oily cosmetics, oily medicines for external application, and the like. Typical examples of oily cosmetics are stick-type cosmetics, e.g. lipsticks, lipcreams, foundation sticks, stick pomade; pencil-type cosmetics, e.g. eyebrow pencil, eyeliner pencil; and pressed powders and oily cake-type cosmetics, e.g. foundations, eyeshadows, rouges. Examples of oily medicines for external application are ointments and the like.
These oily cosmetics are usually prepared by mixing solid fats such as carnauba wax, candelilla wax, ceresine, microcrystalline wax, hydrogenated animal or vegetable fats, bees wax, polyethylene wax, and the like with oils such as castor oil, olive oil, jojova oil, squalane, various synthetic esters, silicone oil, liquid paraffin, and the like, into which powders such as pigments and the like are dispersed as required. There are some oily cosmetics in which semi-solid oils such as vaseline and the like, which show an intermediate characteristics of solid fats and liquid oils, are used in place of the above oil components. Oily medicines for external application are usually produced by kneading pharmaceutical components into the mixed system of the above solid fats and liquid oils.
The oily composition produced from a mixed system of the above solid fats and liquid oils, however, has namely a curd-house structure in which crystals of the solid fats precipitates from the oils of liquid-state. This type of crystals is hard to control and becomes large in size. Hence, oily compositions have resultantly poor transparency and tend to become turbid. In addition, oily compositions must incorporate a relatively greater amount of solid fats for the improvement of shape-retentivity. Such compositions usually become hard, have poor extendibility on the skin, and possess a poor adhesive capability because they lose their uniform structure when applied to. Further, one of the drawbacks of those compositions is that the retentivity of the compositions is reduced after they are applied to the skin because the viscosities of the compositions are lowered.
Therefore, this invention is directed to an oily composition for external application having transparent or semi-transparent appearance and providing excellent retentivity and extendibility on the skin and adhesive capability to the skin.
In view of this situation, the present inventors have conducted extensive studies, and consequently, found that an oily composition for external application having transparent or semi-transparent appearance and providing excellent extendibility and adhesive capability can be obtained by incorporating two kinds of specific fatty acid esters and liquid-state oils in a specific proportion. This finding has led to the completion of the present invention.